The present invention relates to jacking systems and especially to a fluid jacking system for lifting a modular building unit for placement upon and removal from trailer beds for transporting modular units between sites.
In the past, a great many types of jacks have been provided including hydraulic and pneumatic jacks for lifting a great variety of objects. Jacks have also been used to level and support building, mobile homes, and the like. It has further been suggested to use threaded members for adjusting corners of machinery as well as modular building units.
Recently, a great variety of modular and prefabricated homes have been suggested and built in which factory methods are applied to building the whole house or a portion of a house or other modular unit. After the units are built in a factory, they are loaded on a truck, train, boat or other vehicle for movement to the site where the unit is to be placed. The most common type of modular homes are offshoots of the mobile home manufacturers who began building bigger mobile homes for stationary placement and which were not intended to be moved from place to place. Thus, it became a natural offshoot to utilize the same factory type building techniques to build units very similar to mobile homes but not having the wheel base and the necessary supports for the wheels and simply loading the unit on the truck or trailer with an over-head crane for transportation to the site in which it was going to be permanently placed. At the site the unit can be removed by a portable crane placed on the precise location desired for the unit. Inasmuch as these modular units were of light weight construction they could be easily handled by a small crew for placement on a site and leveling. The units were typically made of lightweight sheet metal along with plywood and might typically include lightweight, high strength construction such as honeycomb materials. These units, however, while suitable for residential or vacation type homes, would not meet the more stringent requirements of commercial buildings, motels, schools, and the like. To overcome this limitation certain modular steel buildings were designed which could meet commercial requirements. These buildings were easily placed in position with cranes but were not only expensive but had low fire ratings inasmuch as high temperatures tended to warp the metal making the entire building unusable.
The present invention is directed towards a jacking system for lifting a modular unit made of concrete or concrete block which is designed to meet the requirements of schools, motels or commercial buildings as well as homes which has a higher fire rating but which is also substantially heavier than previous modular units and which is accordingly more difficult to lift and transport. Thus, the present jacking system provides for a building adapted to accept a series of jacks for lifting the building for placing a truck trailer bed under the building unit. The building then has special designed features for distributing the load of the jacks throughout the building framework so that the heavier concrete block structure can be placed upon a truck for transportation and can be easily removed at the site without the necessity of expensive cranes being moved to a particular site for unloading the modular unit from the truck.